This invention relates, in general, to the safety promotion of optical devices and, more particularly, to enhanced safety features of parallel data link communications systems.
Open Fiber Control (OFC) is an ANSI standard method of interlocking Fiber Optic Communication Transmission (FOCT) devices for the express purpose of protecting people from eye damage caused by excessive exposure to dangerous levels of optical frequency (typically 630 nm to 1570 nm) electromagnetic radiation (EMR). An OFC protocol is beneficial in detecting a data channel not completing a loop of data transmission. Reasons for a loss of data include a break in an optical fiber, a cut fiber, or an unattached fiber. The OFC protocol can ensure a parallel link communications system is eye safe with respect to any one of the problems listed above.
Yet, eye safety may not be as high a concern with certain failure means as compared to others. For example, cut, broken, or unattached optical fibers in a location having no human activity could be a low eye safety risk. Yet, one of the above listed problems occurring in a location of high human activity could decrease eye safety in that location.
In addition, the probability of certain failures near optical interconnections could be greater than in remote locations. For example, human contact with optical components is more likely near an interconnect region than in a remote location (i.e., more likely near the end of an optical fiber rather than the middle). Near interconnected devices and areas of higher human activity, an optical fiber connector or optical fiber holding device could become disconnected or detached. As stated before, an OFC integrated circuit could prevent harmful emission of laser light from a device in the event an accident such as those previously mentioned occurs. Yet, an OFC system could provide more safety features than needed and desired (i.e., protection if a problem occurs with an optical fiber itself, in a remote location). OFC systems can be a costly addition to a communications package, as well as adding size to a package profile of a device. For these reasons, an OFC integrated circuit could be too complicated an approach for desired eye safety protection measures.
In this document is described a novel method of promoting eye safety in the event of an unconnected optical fiber holder or fiber connector. The invention could prevent user eye damage if an optical fiber connecting system were disconnected from the optical interface of a device containing an optical transmitter.